Objective: To analyze the risk factors for metastasis of lymph nodes between sternocleidomastoid and sternohyoid muscle (LNSS) in papillary thyroid cancer (PTC). Methods: Papillary thyroid cancer patients with clinically positive lateral lymph node metastasis (cN1) who underwent surgery including LNSS dissection between May 1, 2013 and May 31, 2016 at the Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center were retrospectively studied. Logistic regression analysis was performed to evaluate possible clinicopathological factors related to LNSS metastasis. Results: In 85 patients, 54 patients (63.5%) showed LNSS in their surgical specimen, and 20 patients (23.5%) had pathologically positive LNSS metastasis. Patients with LNSS showed preoperatively higher levels of serum thyroid stimulating hormone (TSH) and thyroid peroxidase antibody (TPO-Ab) compared to patients only with fibrofatty tissues between sternocleidomastoid and sternohyoid muscle (P<0.05), and they also displayed a higher proportion of multifocality in ipsilateral thyroid lobe (P<0.05). Multi-factor analysis indicated that LNSS metastasis was correlated with original tumor size (OR=1.819, 95%CI 1.050-3.850, P=0.002) and Level Ⅳ lymph node metastasis (OR=2.190, 95%CI 1.132-2.334, P=0.005). Furthermore, the number of positive LNSS was tightly correlated to that of level Ⅳ lymph node metastasis(P<0.05). Conclusion: LNSS metastasis is occult but not quite rare in PTC. Patients with extensive lymph node metastasis in Level Ⅳhave a higher risk for metastasis of LNSS.
目的： 分析甲状腺乳头状癌(papillary thyroid cancer, PTC)中胸锁乳突肌-胸骨舌骨肌间(lymph node between sternocleidomastoid and sternohyoid muscle，LNSS)淋巴结转移的危险因素。 方法： 回顾性分析复旦大学附属肿瘤医院头颈外科2013年5月1日至2016年5月31日行手术治疗且有LNSS分区的颈侧cN1 PTC患者，采用Logistic回归分析与LNSS相关的临床病理学因素。 结果： 85例患者中LNSS存淋巴组织者54(63.5%)例，病理确诊阳性20(23.5%)例。清扫见淋巴组织组患者术前血清促甲状腺激素(thyroid stimulating hormone，TSH)水平、甲状腺过氧化物酶抗体(thyroid peroxidase antibody, TPO-Ab)水平明显高于纤维脂肪组织组(P<0.05)，同时患侧多病灶比例高(P<0.05)。多因素分析提示54例患者中LNSS转移与原发肿瘤大小(OR＝1.819，95%CI 1.050～3.850，P＝0.002)及Ⅳ区淋巴结转移(OR＝2.190，95%CI 1.132～2.334，P＝0.005)相关，且LNSS阳性数目与Ⅳ区阳性数目密切相关(P<0.05)。 结论： PTC患者LNSS淋巴结转移隐匿但并非少见，对于颈侧Ⅳ区淋巴结转移明显者更应注意LNSS转移的风险以保证手术彻底性。.
Keywords: Lymph node between sternocleidomastoid and sternohyoid muscle; Neck dissection; Risk factors; Thyroid neoplasms.